EP 1,737,616 A1 discloses a hand-held power tool which transmits a driving force of a driving motor to a spindle to drive a tool accessory. In this power tool, a clamp shaft extends through the spindle and holds the tool accessory. The clamp shaft is configured to be movable between a holding position for holding the tool accessory and a releasing position for releasing the tool accessory and to engage in the holding position with a lock mechanism provided inside the spindle.